CA2265280C - Alkaline secondary battery - Google Patents

Abstract

The present invention is directed to an alkaline secondary battery comprising a positive electrode, a zinc based negative electrode, and an alkaline electrolyte solution, wherein the positive electrode includes a central cavity for receiving the zinc based negative electrode, and the negative electrode includes a central cavity for holding the alkaline electrolyte solution. The battery is arranged such that the positive electrode presents a smaller capacity than the negative electrode at least in an initial charge/discharge period.

Description

CA 02265280 l999-03- 12TITLE OF THE INVENTIONALKALINE SECONDARY BATTERYBACKGROUND OF THE INVENTIONField of the InventionThe present invention relates generally to analkaline secondary battery including a positive electrode,a negative electrode and an alkaline electrolyte solution,and particularly to an alkaline secondary battery whichemploys zinc as a negative electrode material for use inthe negative electrode and which provides satisfactorycharge/discharge cycle performance in a case where thepositive electrode is adapted to present a smaller capacitythan the negative electrode at least in an initialcharge/discharge period and the negative electrode containszinc in an increased proportion for increase in the batterycapacity.Description of the Related ArtHeretofore, the alkaline secondary batteries haveemployed various materials as the negative electrodematerial for use in the negative electrode.An alkaline secondary battery of high energy densityis obtained by the use of zinc with a small electrochemicalequivalent and electrode potential as the negative-electrode material.In this connection, various studiesCA 02265280 l999-03- 12have long been made on the alkaline secondary batteriesemploying zinc as the negative—electrode material.There has been disclosed in Japanese Examined PatentPublication No.45(1970)—357O an alkaline secondary batteryof a so-called inside—out construction which includes acylindrical positive electrode with a central cavity, and anegative electrode comprised of a bar—like negative-electrode current collector and a zinc layer, as thenegative—electrode material, formed around the currentcollector, the negative electrode received by the centralcavity of the positive electrode (so called outside-positive electrode cell).The alkaline secondary battery of such an inside—outconstruction features a high energy density by virtue of agreat amount of negative—electrode and positive—electrodematerials contained in the battery. Unfortunately,repeated charge/discharge cycles result in shortage of thealkaline electrolyte solution in the zinc based negativeelectrode. Consequently, the battery is lowered in thecharge/discharge cycle performance.As a solution to this problem, Japanese ExaminedPatent Publications No.45(1970)—4254 and No.45(1970)—17332have proposed alkaline secondary batteries of inside—outconstruction which each include a cavity for holding thealkaline electrolyte solution or water to be fed to theACA 02265280 l999-03- 12negative electrode, thereby achieving improvedcharge/discharge cycle performance.However, in a case where the cavity for holding thealkaline electrolyte solution or water is disposed abovethe negative electrode as suggested by Japanese ExaminedPatent Publication No.45(1970)—4254, the negative electrodeis not sufficiently supplied with the alkaline electrolytesolution at a portion around the negative—electrode currentcollector which is spaced away from the positive electrode.Consequently, the battery fails to achieve an adequateimprovement in the charge/discharge cycle performance.It is to be noted that the alkaline secondarybatteries disclosed in the above official gazettes employmanganese dioxide as the positive electrode material foruse in the positive electrode.Unfortunately, manganese dioxide has a poorreversibility of the charge/discharge reaction process.Hence, such an alkaline secondary battery normallyrestricts the capacity of the zinc based negative electrodewithin the range of a chargeable/dischargeable capacity ofthe manganese—dioxide based positive electrode. As aresult, a satisfactory battery capacity cannot be obtained.on this account, the current trend of the alkalinesecondary battery is to use nickel hydroxide as thepositive electrode material for use in the positiveCA 02265280 l999-03- l2electrode. In a case where nickel hydroxide, having asuperior charge/discharge characteristic to manganesedioxide, is used as the positive electrode material, thecapacity of the positive electrode may be restricted withinthe range of a chargeable/dischargeable capacity of thezinc based negative electrode. Thus, the satisfactorycharge/discharge capacity may be obtained by increasing theamount of zinc contained in the negative electrode.The charge/discharge reaction process occurring inthe battery having the nickel—hydroxide based positiveelectrode is expressed by the following chemical formula,wherein the discharge reaction process involves the loss ofwater in the alkaline electrolyte solution:Ni(OH)2+Zn(OH) 2¢» NiooH+zn+2Hg3Accordingly, the alkaline secondary batteryemploying nickel hydroxide as the positive electrodematerial has a detrimental tendency of suffering shortageof the alkaline electrolyte solution during the dischargeprocess. In the negative electrode, on the other hand, azinc dissolution/deposition process takes place inconjunction with the charge/discharge reaction process.Thus, in conjunction with repeated charge/dischargeprocesses, the repeated zinc dissolution/depositionprocesses cause gaps between zinc particles to becomeblocked and passivated. This interferes with permeation ofCA 02265280 l999-03- 12the alkaline electrolyte solution into the negativeelectrode, resulting in a battery capacity decline.Particularly, in the case of the alkaline secondary batteryof inside—out construction with the negative electrodecontaining the increased amount of zinc for achieving thesufficient charge/discharge capacity, a serious decline inthe battery capacity results from the zinc passivationresluting from the charge/discharge process. As a result,the alkaline secondary battery is lowered in thecharge/discharge cycle performance.SUMMARY OF THE INVENTIONOne objective of the invention is an alkalinesecondary battery of inside—out construction in which azinc based negative electrode is received by a centralcavity of a positive electrode, the battery being adaptedto prevent the shortage of alkaline electrolyte solutionduring the charge/discharge process and the decline in thebattery capacity resulting from the zinc passivation whichmay occur in the charge/discharge process.Another objective of the invention is the alkalinesecondary battery of inside—out construction in which thezinc based negative electrode is received by the centralcavity of the positive electrode, the battery ensuring theCA 02265280 l999-03- l2sufficient battery capacity and the excellentcharge/discharge cycle performance.The alkaline secondary battery according to theinvention comprises a positive electrode, a zinc basednegative electrode and an alkaline electrolyte solution,the positive electrode including a central cavity forreceiving the zinc based negative electrode, the negativeelectrode including a central cavity for holding thealkaline electrolyte solution, the positive electrodepresenting a smaller capacity than the negative electrodeat least in an initial charge/discharge period.If the alkaline secondary battery has the inside—outconstruction wherein the positive electrode includes thecentral cavity for receiving the zinc based negativeelectrode, as suggested by the invention, an increasedamount of zinc may be contained in the negative electrode.This ensures the sufficient battery capacity when thepositive electrode employs nickel hydroxide as thepositive—electrode material and has a capacity thereofrestricted within the range of a chargeable/dischargeablecapacity of the negative electrode.If the negative electrode includes the centralcavity for holding the alkaline electrolyte solution, assuggested by the alkaline secondary battery of theinvention, the alkaline electrolyte solution will not runCA 02265280 l999-03- 12short during the discharge process. In addition, thenegative electrode is sufficiently supplied with thealkaline electrolyte solution at the central portionthereof, which is spaced away from the positive electrode.Thus is prevented the zinc passivation leading to thebattery capacity decline and hence, the charge/dischargecycle performance is improved.If, in the negative electrode, the central cavityfor holding the alkaline electrolyte solution has too greata volume, the negative electrode can contain a decreasedamount of zinc and hence, the sufficient battery capacitycannot be attained. If, on the other hand, this centralcavity is insufficient in volume, the cavity can hold adecreased amount of alkaline electrolyte solution, failingto sufficiently supply the negative electrode with thealkaline electrolyte solution. Thus, the loweredcharge/discharge cycle performance results. Accordingly,the ratio (=V2/V1) of a volume V2 of the cavity for holdingthe alkaline electrolyte solution to a volume V1 of thenegative electrode minus the cavity for holding thealkaline electrolyte solution is preferably in the range of0.10 to 0.60.In a case where a negative—electrode currentcollector is disposed on an inside surface of the negativeelectrode which surface defines the cavity for holding theCA 02265280 l999-03- l2alkaline electrolyte solution, the negative—electrodecurrent collector should permit the alkaline electrolytesolution to pass bi—directionally therethrough, therebyfeeding the alkaline electrolyte solution to the insideportion of the negative electrode. For instance, thecurrent collector may be formed of a cylindrical metalsheet formed with holes permitting the bi—directionalpassage of the alkaline electrolyte solution.Where the negative—electrode current collector isdisposed circumferentially within the negative electrode,the negative—electrode current collector is preferablyplated with indium for prevention of hydrogen gas evolutionwhich occurs in the negative electrode and results in these1f—discharge.If a small gap is defined between the positiveelectrode and the zinc based negative electrode received bythe aforesaid cavity of the positive electrode, a decreasedamount of alkaline electrolyte solution is poured into thealkaline secondary battery. If, on the other hand, the gapbetween the positive electrode and the negative electrodeis too great, a decreased amount of negative—electrode andpositive—electrode materials is packed in the alkalinesecondary battery. This results in a decreased batterycapacity. Accordingly, the ratio (=d/D) of an outsidediameter d of the negative electrode to an inside diameterCA 02265280 l999-03- 12D of the positive electrode is preferably satisfies thefollowing condition:0.58 < d/D < 0.76.In the alkaline secondary battery according to theinvention, the positive electrode may employ the positive-electrode material generally used in the alkaline secondarybatteries, such as manganese dioxide, nickel hydroxide andthe like. For enhancement of the charge/discharge capacityof this alkaline secondary battery, it is preferred thatthe positive electrode employs nickel hydroxide as thepositive—electrode material and has its capacity restrictedwithin the range of a chargeable/dischargeable capacity ofthe negative electrode whereas the negative electrode‘contains an increased amount of zinc.i For achievement ofthe sufficient charge/discharge capacity and prevention ofthe oxygen evolution in the charge process, it isparticularly preferred to use such a positive—electrodematerial as has a crystal structure which is transformedinto a y—NiOOH structure when charged.These and other objects, advantages and features ofthe invention will become apparent from the followingdescription thereof taken in conjunction with theaccompanying drawings which illustrate specific embodimentsof the invention.CA 02265280 1999-03-l2BRIEF DESCRIPTION OF THE DRAWINGSFig.1 is a schematic sectional View showing aninternal construction of an alkaline secondary batteryaccording to an embodiment of the invention; andFig.2 is a schematic sectional view showing aninternal construction of an alkaline secondary batteryaccording to a comparative example hereof.DESCRIPTION OF THE PREFERRED EMBODIMENTSThe following examples specifically illustrate thealkaline secondary battery according to the invention withreference to the accompanying drawing. Further,comparative examples are given to clarify that the alkalinesecondary batteries of examples hereof present excellentcharge/discharge performance. It is to be noted that thealkaline secondary battery according to the invention isnot limited to the following examples but variations andmodifications thereto may be made within the scope andspirit of the invention.(Examples 1 to 8)In Examples 1 to 8, a positive electrode and anegative electrode were prepared in the following mannersand were used for fabrication of an AA-size alkalinesecondary battery of inside—out type construction as shownin Fig.1.10CA 02265280 l999-03- 12(Preparation of Positive Electrode)The positive electrode was prepared in the followingmanner. To a solution mixture containing 0.2 mol/1 nickelsulfate and 0.1 mol/1 manganese sulfate, there was added asolution mixture containing 10% ammonia and 10% sodiumhydroxide. The pH of the resultant solution mixture wasadjusted to 10.0:0.4 thereby to obtain a precipitate. Theprecipitate was filtered off and then was kept in a 20% KOHaqueous solution at room temperature for one week.Subsequently, the precipitate was washed and filtered off,thereby to obtain the positive-electrode material.The X—ray diffraction (XRD) was used to study acrystal structure of the positive-electrode material tofind that this material had an a—Ni(OH), crystal structure.On the other hand, the positive-electrode material wasstudied by using the electron probe microanalysis (EPMA).It was determined that this a-Ni(OH), formed a solidsolution with manganese. Further, the positive-electrodematerial was analyzed by atomic absorption spectrometry todetermine that manganese was contained in a concentrationof 25 wt% based on total weight of nickel and manganese.Subsequently, 10 wt% NaClO aqueous solution wasadjusted to maintain pH 12 by adding sodium hydroxide. Inthis aqueous solution, the aforesaid solid solution a-Ni(OH)2 incorporating manganese was subject to an oxidation11CA 02265280 l999-03- 12treatment in which the aforesaid a—Ni(OH), was oxidized toy—NiOOH.Then, 45 parts by weight of a—Ni(OH), thus obtained,45 parts by weight of y-NiOOH thus obtained, and 10 partsby weight of graphite were mixed together and was press-molded into a cylindrical positive electrode 1 having anoutside diameter of 13.3mm, an inside diameter of 10.3mmand a height of 13.5mm, as shown in Fig.1.(Preparation of Negative Electrode)Preparatory to the preparation of the negativeelectrode, a negative electrode mixture was prepared in thefollowing manner. Zn and Zno or Zn(OH),were mixedtogether in a weight ratio of 2:1. To this mixture, 2.5wt% of Inga for suppressing the hydrogen gas evolution,1.0 wt% of carboxymethylcellulose as a binder, and 0.5 wt%of polytetrafluoroethylene were added. A suitable amountof water was added to this mixture such that a weight ratioof water was about 1/5 based on negative—electrodematerial. The resultant mixture was kneaded thereby toobtain the negative electrode mixture.Then, an indium—plated copper lath was used as thenegative-electrode current collector. This negative-electrode current collector was wound around each core barof each predetermined diameter. The aforesaid negativeelectrode mixture was press—fitted around each current12CA 02265280 l999-03- l2collector and then, the core bar was removed to give acylindrical negative electrode 2 with a negative—electrodemixture layer 2a formed around the negative-electrodecurrent collector 2b, as shown in Fig.1.In Examples 1 to 8, the diameter of the core bar andthe thickness of the negative electrode mixture press-fitted over the negative—electrode current collector werevaried thereby to obtain the negative electrodes of therespective examples with the outside diameters and insidediameters shown in Table 1 as below. For each of thenegative electrodes thus obtained, the ratio (=V2/V1) of avolume V2 of the central cavity of the negative electrodeto a volume V1 of the negative electrode minus the centralcavity thereof was determined. The results are shown inTable 1 as below.(Fabrication of Battery)The battery was fabricated in the following manner.As shown in Fig.1, the cylindrical positive electrodepieces 1, stacked in three layers, were placedcircumferentially within a battery case 3. A separator 4formed of laminated cellophane and a vinylon unwoven fabricwas inserted in the positive electrode with the vinylonunwoven fabric contacting the positive electrode. Each ofthe aforesaid negative electrodes 2 was placedcircumferentially within the positive electrode 1 with the13CA 02265280 l999-03- l2separator 4 interposed therebetween. In this state, analkaline electrolyte solution 5 composed of 40 wt% KOHaqueous solution was poured into each battery case 3 untilthe positive electrode 1 and the negative electrode 2 werecompletely immersed therein. Thus, the positive electrode1 and negative electrode 2 were impregnated with thealkaline electrolyte solution 5 while the alkalineelectrolyte solution 5 was allowed to fill gaps on aninterior circumferential side of the negative electrode andbetween the positive electrode 1 and the negative electrode2. Thereafter, each of the battery cases 3 was sealed andthus was completed an AA—size alkaline secondary batterywith a battery capacity of about 1000 mAh in accordancewith each of Examples 1 to 8;For each of the alkaline secondary batteries thusfabricated, the ratio (=d/D) of an outside diameter d ofthe negative electrode to an inside diameter D of thepositive electrode was determined. On the other hand, atheoretical capacity Qc of the positive electrode and atheoretical capacity Qa of each negative electrode werecalculated so as to find a ratio (=Qa/QC) of thetheoretical capacity Qa of each negative electrode to thetheoretical capacity Qc of the positive electrode.Further, an amount of alkaline electrolyte solution pouredinto each alkaline secondary battery was determined. The14CA 02265280 l999-03- 12results are shown in Table 1 as below. The ratio (=Qa/Qc)of the theoretical capacity Qa of each negative electrodeto the theoretical capacity Qc of the positive electrodewas determined as follows. A content of a—Ni(OH), and Y-NiOOH in the positive electrode was calculated on an a-Ni(OH), basis to determine that each of the aforesaidalkaline secondary batteries contained 3.6g of a—Ni(OH)2.Given that a—Ni(OH)2 had a theoretical capacity per unitweight of 289 mAh/g, the theoretical capacity of thepositive electrode was determined to be 1040 mAh. As tothe negative electrode, contents of Zn and ZnO weredetermined based on weight. The theoretical capacity Qa ofeach negative electrode was determined by using thecontents of Zn and ZnO thus determined, a per-unit—weighttheoretical capacity of Zn at 820 mAh/g, and a per—unit—weight theoretical capacity of Zno at 658 mAh/g.(Comparative Examples 1 to 3)In Comparative Examples 1 to 3, negative electrodeswere prepared in the following manner. The negativeelectrode mixture was prepared in the same way as inExamples 1 to 8 whereas a 1mm—diameter copper bar was usedas the negative—electrode current collector. As shown inFig.2, the negative electrode mixture 2a was press—fittedaround the bar—like negative—electrode current collector 2bin each predetermined thickness. Thus were prepared the15CA 02265280 l999-03- 12negative electrodes 2 with outside diameters shown in Table1 as below.The alkaline secondary batteries were fabricated inthe same manner as in Examples 1 to 8, except for that thenegative electrodes 2 thus prepared were used.For each of the alkaline secondary batteries ofComparative Examples 1 to 3, the ratio (Qa/QC) of atheoretical capacity Qa of each negative electrode to thatQc of the positive electrode as well as the amount ofalkaline electrolyte solution poured into each alkalinesecondary battery were determined in the same way as inExamples 1 to 8. The results are shown in Table 1 asbelow.The fabricated alkaline secondary batteries ofExamples 1 to 8 and Comparative Examples 1 to 3 were eachsubject to 30 charge/discharge cycles. onecharge/discharge cycle consisted of charging the battery ata charge current of 200mA to a battery voltage of 1.95V,followed by discharging the battery at a discharge currentof 200mA to a battery voltage of 1.0V. For each alkalinesecondary battery, a battery capacity Q1 on the first cycleand a battery capacity Q30 on the 30th cycle weredetermined.The results are also shown in Table 1 asbelow.16CA 02265280 l999-03- 12(Table 1)negative amount. ofelectrode v2/v1 d/ D Qa/Qc efe1c’§j‘r1;1"y:e cbafiatceiiyy(mm) solution(9outside insidediameter diameter Q1 Q3 0Exmufle 1 6.0 1.0 0.03 0.58 3.5 2.7 1000 660Exmuflez 6.0 1.9 0.10 0.58 3.2 2.8 1000 790Example3 6.0 2.8 0.22 0.58 2.8 2.9 1010 820ExmQfle4 6.0 3.6 0.36 0.58 2.3 3.2 1020 810Exmuues 6.0 4.6 0.60 0.58 1.5 3.3 1010 800Exmqde 6 6.0 4.8 0.64 0.58 1.3 3.4 1000 730Exmmfle7 7.0 2.2 0.10 0.68 4.0 2.7 1020 840Exmqfle 8 7.8 2.4 0.10 0.76 5.0 2.6 1040 780ComparativeExample 1 6 ' 0— — 0.58 3.5 2.5 1000 430ComparativeExample 2 7 ' 0— — 0.68 4.8 2.3 1010 380Comparative 7 8Example 3 '— — 0.76 6.0 2.1 1040 310According to the results, each of the alkalinesecondary batteries of Examples 1 to 8, wherein eachnegative electrode 2 included the central cavity forholding the alkaline electrolyte solution 5, achieveddramatic improvement in the charge/discharge cycleperformance with notably reduced decline in the batterycapacity Q30 on the 30th cycle, as compared with the17CA 02265280 l999-03- l2alkaline secondary batteries of Comparative Examples 1 to 3wherein each negative electrode 2 included the bar—likenegative—electrode current collector 2b at the centerthereof.A comparison was made among the alkaline secondarybatteries of Examples 1 to 6 each having the negativeelectrode 2 with the 6.0mm outside diameter. The batteriesof Examples 2 to 5, wherein each negative electrode had theinside diameter in the range of 1.9 to 3.6mm and the ratio(=V2/V1) of the volume V2 of the central cavity to that V1of the negative electrode minus the central cavity in therange of 0.10 and 0.60, achieved even greater improvementin the charge/discharge cycle performance with even smallerdecline in the battery capacity Q30 on the 30th cycle, ascompared with the battery of Example 1 having the volumeratio of less than 1.10 and the battery of Example 6 havingthe volume ratio of greater than 0.60.Further, a comparison was made among the alkalinesecondary batteries of Examples 2, 7 and 8 wherein theratio of the volume of the central cavity to the volume ofthe negative electrode minus the central cavity was at 0.1.In the battery of Example 8 having the negative electrode 2of the greatest outside diameter d and the ratio d/D of0.76, the battery capacity Q1 on the first cycle was greatbut the battery capacity Q30 on the 30th cycle was18CA 02265280 l999-03- l2comparable to that of the battery of Example 2 having thenegative electrode of the smallest outside diameter d andthe ratio d/D of 0.58. This is because the gap between thepositive electrode 1 and the negative electrode 2 was sosmall that the reduced amount of alkaline electrolytesolution was poured into the battery. In contrast, thebattery of Example 7, which had the negative electrode ofan intermediate outside diameter d and the d/D ratio of0.68, presented a relatively great battery capacity Q1 onthe first cycle and suffered less decline in the batterycapacity Q30 on the 30th cycle. Thus, the battery of_Example 7 achieved the sufficient battery capacity andexcellent charge/discharge cycle performance.(Example 9)In Example 9, an alkaline secondary battery wasfabricated in the same manner as in Example 3, except forthat the negative electrode 2 was prepared by using anindium—plating—free copper lath as the negative—electrodecurrent collector 2b.Similarly to the above, the alkaline secondarybatteries of Examples 3 and 9 were each subject to a firstcharge/discharge cycle, which consisted of charging at thecharge current of 200mA to the battery voltage of 1.95V andthen discharging at the discharge current of 200mA to thebattery voltage of 1.0V. Subsequently, each of the19CA 02265280 l999-03- l2batteries was charged in the same manner as in the firstcycle. In this state, the alkaline batteries were storedat 60°C for 14 days. Then, the batteries were studied onrespective residual capacity ratios thereof.According to the results, the alkaline secondarybattery of Example 3, which employed the indium-platedcopper lath as the negative-electrode current collector 2b,presented a residual capacity ratio of 85%. On the otherhand, the alkaline secondary battery of Example 9, whichemployed the indium—plating—free copper lath as thenegative-electrode current collector 2b, presented thelower residual capacity ratio of 54%.It is believed that the indium-plated copper lath,which the alkaline secondary battery of Example 3 used asthe negative-electrode current collector 2b, served tosuppress the hydrogen gas evolution in the negativeelectrode 2 thereby preventing the self—discharge of thenegative electrode 2 when the charged battery was stored athigh temperature. In contrast, the indium plating—freecopper lath, which the battery of Example 9 used as thenegative-electrode current collector 2b, detrimentallypermitted the hydrogen gas evolution and the self—dischargeof the negative electrode 2 when the charged battery wasstored at high temperature.20CA 02265280 l999-03- 12Although the present invention has been fullydescribed by way of examples, it is to be noted thatvarious changes and modifications will be apparent to thoseskilled in the art.Therefore, unless otherwise such changes andmodifications depart from the scope of the presentinvention, they should be construed as being includedtherein.21

Claims (10)

The embodiments of the present invention in which an exclusive property or privilege is claimed are defined as follows:

1. An alkaline secondary battery comprising a positive electrode, a zinc based negative electrode, and an alkaline electrolyte solution, wherein said positive electrode includes a central cavity for receiving the zinc based negative electrode, the negative electrode includes a central cavity for holding the alkaline electrolyte solution, and the positive electrode presents a smaller capacity than the negative electrode at least in an initial charge/discharge period wherein said positive electrode employs a positive electrode material whose crystal structure is transformed into a .gamma.-NiOOH structure when charged.

2. The alkaline secondary battery of claim 1, wherein said positive electrode, negative electrode and alkaline electrolyte solution are contained in a battery case, and this battery case contains not less than 70 vol%, in total, of positive electrode material for the positive electrode and negative electrode material for the negative electrode.

3. The alkaline secondary battery of claim 1 or 2, wherein the ratio (=V2/V1) of a volume V2 of the negative electrode cavity for holding the alkaline electrolyte solution to a volume V1 of the negative electrode minus the cavity for holding the alkaline electrolyte solution is in the range of 0.10 to 0.60.

4. The alkaline secondary battery of any one of claims 1 to 3, wherein a negative-electrode current collector permitting bi-directional passage of the alkaline electrolyte solution is disposed on an inside surface of the negative electrode including the cavity for holding the alkaline electrolyte solution.

5. The alkaline secondary battery of claim 4, wherein said negative-electrode current collector is plated with indium.

6. The alkaline secondary battery of claim 3, wherein a negative-electrode current collector permitting bi-directional passage of the alkaline electrolyte solution is disposed on an inside surface of the negative electrode including the cavity for holding the alkaline electrolyte solution.

7. The alkaline secondary battery of claim 6, wherein said negative-electrode current collector is plated with indium.

8. The alkaline secondary battery of claim 1, wherein the ratio (=d/D) of an outside diameter d of said negative electrode to an inside diameter D of said positive electrode including the central cavity satisfies the following condition: 0.58 < d/D < 0.76.

9. The alkaline secondary battery of claim 8, wherein a negative-electrode current collector permitting bi-directional passage of the alkaline electrolyte solution is disposed on an inside surface of the negative electrode including the cavity for holding the alkaline electrolyte solution.

10. The alkaline secondary battery of claim 9, wherein said negative-electrode current collector is plated with indium.